Wattmeter.



C. R. DARGY.

WATTMETER.

APPLICATION FILED JAN. 18, 1910.

1,003,883. 1 Pa nted Sept. 19,1911.

l 9 12V SZE'NTDR m LIZ-57L R. 171 11201 UNITED STATES PATENT OFFICE.

CECIL R. DARCY, OEWOLSTON, NEAR COVENTRY, ENGLAND; ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK..

WATTMETER.

Specification of Letters Patent.

Patented Sept. 19, 1911.

Application filed January 18, 1910. Serial No. 538,723.

and compact construction which shall have its operating parts readily accessible.

I accomplish the objects of my invention by the use of a special form of magnetic core wherein the fluxes, due to the potential and the series windings, flow at right angles to each other, that is, the planes of the magnetie.oircuits for these windings are at right angles to each other, and by using that portion of the core energized by the series winding for also carrying the potential flux, and

by a special arrangement of the meter parts.

The further novelties of my invention are described with more particularity in the claim annexed to and made a part of this specification.

For a better wider-standing of my invention, reference may be had to the accompanying drawings where- Figure 1 shows a vertical view partly in section of a meter built in accordance with my invention, the front part of the casing being removed; Fig. 2 shows a front view of the essential elements of the meter; and Fig. 3 shows a modification of the magnetic circuit.

Referring first to Figs. 1 and 2, 1 is a casing of the meter which may. be made of magnetic material. The casing is provided with holes 2, only one of which is shown,

for the screws by which it is supported. Formed integral with the casing are bosses 3 and thcvprojectionf twhieh is made of magnetic material. The potential core 5 is formed of suitable laminations in the usual manner secured together by plate 6 and screws at the upper portion thereof and bybrackets 8 and screws 9, at the lower portion. Brackets 8 are secured to bosses 3 by screws 10. Potential coil 11 surrounds one leg of the substantially U-shaped core so as to form potential ole 11. In operative relation with this p0 e is an armature 12 which may be of the usual disk type carried by shaft 13 which is provided with a worm 1 1 which drives suitable registering mechanism contained in the fralne-worlclo. This mechanism and the bearings for the meter shaft may be constructed in any of the well known manners. In operative relation with armature 12 is a damping magnet 16, which may be constructed in the usual manner. The damping magnet, armature and shaft and registering mechanism are supported by the bracket 17 which is fastened to easing 1 by screws 18 which are tapped into suitable projections provided for the purpose in the meter easing.

Below the armature in operative relation therewith and facing the potential pole is a series core 19 which consists of two poles 19 which, are energized by the sericscoils 20,

these coils being wound soas to make the poles of opposite polarity. The inner corners of these poles are chamfered and the series coils are so arranged that their ends nearest the armature are quite flush with pole faces in order to reduce the leakage of the current flux beneath the disk. The laminations composing the series core are fastened to bracket 4 by means of screws 4', which screws may pass through slots in the core, not shown, to allow adjustment of the core to and from the armature disk.

The potential pole is surrounded by lagging coil 21 WhlCll is preferably stamped on a sheet of low resistance material and is provided with a flange 22 and lugs 23. This flange is slotted with two slots 24 to allow clamping screws 25 to pass through. These screws are tapped into the laminations of the potential pole and so arranged that when they are slightly unscrewed, coil 21 may-be moved tothe right or to the left and then held in any desired position by tightening screws 25. Set screws 26 are tapped into lugs 23 and engage with the potential pole and are used for adjusting the position of coil 21 in the well known manner.

In addition to. the magnetic circuit for the potential coil passing through the armature, there is provided by means of magnetic member 27 a shunt path for the potcntial flux around the armature, with an tain a correct phase adjustment when the meter. is used with diflerent frequencies, a copper plate or sliding piece 29 is arranged to slide in gap 28 of the shunt magnetic circuit. This plate has at one side an arm, in which are screwed the ends of screws 31. In operative relation with this arm and the screws is a fixed member 29" (see Fig. 2), having a slot'30, through which the screws pass and along which they slide. \Vhen screws 31 are not screwed tight, t-he plate may be readily moved until the correct adjustment for the frequency desired is obtained, whereupon screws 31 may be tightened, thus holding the plate rigidly fixed against member 29 in the usual manner. It will be obvious that the path of the magnetic circuit for the potential field is through the magnetic member 5, part of easing 1, magnetic bracket 4 and through core 19, and also is through the shunt path 27. The path of the magnetic circuit for the series coils is through the series coil 19 at right angles to the path of the magnetic circuit for the potential field. It will be also obvious that the potential and series coils, the lagging coil 21 and the frequency correcting plate 29 are readily accessible by removing bracket 17 which is held by screws 18.- v

I find by this arrangement of the mag n'etic circuit and of the supporting means for the armature registering and damping ma nets, I am able to construct a meter which is at the same time accurate and substantial, in a very simple manner.

While I have shown magnetic bracket 4 as formed integral with the casing such Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

may be formed as a separate member and bolted to the casing, as bracketsBare bolted to the casing, and I have not illustrated this construction. Further, as shown in Fig. 3, I may modify the construction shown in Fig. l somewhat, by not using a portion of the meter casing as part of the magnetic circuit but by continulng punchings 5 with extensions 5 in the manner shown in Fig. 3. With this construction I may, if I so desire, construct a meter with the same general arrangement of magnetic circuit but without employing the casing as part of the same and therefore I may use a casing of non-magnetic material.

What I claim as new and desire to secure by Letters Patent of the United States, 1S:

In an electric meter, a casing, potential and series windings, a magnetic circuit" therefor comprising potential and series magnetic cores, the paths of the potential and series magnetic circuits being. at right angles to each other, an armature in operative relation with the potential and series windings, damping means and a registering mechanism in operative relation with the armature, and a bracket supporting the damping means and the registering mechanism removably attached to the casing.

In witness whereof,-I have hereunto set my hand this thirtieth day of December,

CECIL R. DARGY.

Witnesses: I I

CHARLES H. FULLER, J. A. FOSTER.v

Washington, D. G. 

